Way back when Doug was in nickers. And commercial aviation was just getting started, they found a problem with too much alcohol and high altitudes. Many aircraft had to make emergency landings because of someone having too much to drink. Yes this was in the era before jets.. The FAA stepped in and say's you can only have x number of drinks per hour/flight To keep an eye on you, you can only buy drinks. This also helps to reduce the # of folks that get rowdy when they have too much to drink. "Taking it Outside" at 30,000 feet is not really an option. 3 hours on a plane with a rowdy drunk in no fun either. L.B.